“Cleaner Times,” published by Advantage Publishing Co. Inc., Little Rock, Ak. is a monthly publication of the technical journal of the high pressure water applications industry. Rotary pressure cleaning machines are well known within this large industry.
The machines usually have handlebars to control a spray head. The spray head has a hood or shroud that encloses a rotary spray bar or spinner bar which carries spray nozzles. The spray head may be mounted on wheels or it may float on the residual pressure from the spray nozzles. Pressurized liquid is supplied through the spray head and spinner bar to the nozzles, via a standard engine and pump configuration, to produce a spray that accomplishes the work of cleaning a surface over which the machine is maneuvered. The spinner bar may be rotated by the reaction force of the spray nozzles or it may be independently powered, as by the combination of a belt and motor, or both.
U.S. Pat. No. 4,191,590 to Sundheim is typical of such machines and discloses a spinner bar with two nozzles, one at each end of the bar. The nozzles may be adjusted as to the angle of inclination in regard to the plane of rotation, the spray pattern, flow rate, and spray arc. U.S. Pat. Nos. 6,370,728; 5,135,015; and 6,012,645 are each directed to a rotary machine having a spinner bar and one nozzle on each end. U.S. Pat. No. 5,265,805 is directed to a rotary machine with a three bladed spinner bar with one nozzle at each of the three ends.
There are certain shortcomings in the rotary pressure cleaning art which result in a non-uniform appearance of a cleaned surface and cause the machines to create excessive noise. The prior art machines are also generally restricted to hard surfaces due to the high pressure impact of the liquid upon a small area. The construction of the prior art devices deliver cleaning spray to a small impact area causing uneven application of the cleaning spray resulting in stripes and swirls on the cleaned surface. The small impact area also causes the prior art machines to have a high noise level and is also inefficient and usually requires retracing for adequate cleaning of a surface.
In the normal use of all rotary cleaners, the spray head is moved over a surface in a pattern of passes. Because of the rotation of the spray bar, each pass leaves a cleaned path the length of the pass and the width of the diameter of the spray bar. To clean a large area, a number of passes must be made with the edge of a later path overlapping the edge of an earlier path. This overlapping causes the same area of the surface to be cleaned more than once.
Conventional machines have a common problem of overlapping paths producing a series of stripes and swirls of extra-clean surface which contrasts with the remainder of the surface. To overcome this nonuniformity of color, the surface must be retraced until the stripes are obliterated or reduced. Regardless of the pattern of passes, straight, rectangular, or circular, the stripes or swirls created require more time and repetition to produce an acceptable uniform cleaned surface. This repetition results in increased labor costs and wear on the machines.
Because of the high pressures, for example 200-5000 psi, there is a significant level of noise during the use of the machine. Also, having a nozzle on each end of a two bladed or three bladed spray bar produces a small cleaned area equal to the narrow spray coverage as the spray bar rotates resulting in a particular time frame for cleaning a large surface. This high pressure limits the surfaces that the conventional machines can be used to clean without damaging the substrate, for example some nozzles will scour grout from between tiles, score soft woods for decks, or remove particles from roofing shingles.
What is needed in the art is a surface cleaner that has a lower noise level, accomplishes work faster, produces a uniform cleaned surface and can be used on softer surfaces.